<!--
 * @Author: 杨文涓 943701297@qq.com
 * @Date: 2022-04-20 08:53:52
 * @LastEditors: 杨文涓 943701297@qq.com
 * @LastEditTime: 2022-05-07 14:43:44
 * @FilePath: \Webc:\Users\94370\Desktop\面向工作学习\html css\5-CSS 三（第五天）\21-块级盒子水平居中对齐.html
 * @Description: 
 * 
 * Copyright (c) 2022 by 杨文涓 943701297@qq.com, All Rights Reserved. 
-->
<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>块级盒子水平居中对齐</title>
    <style>
        div {
            width: 90px;
            height: 90px;
            background-color: blue;
            margin: 100px auto;
        }
    </style>
</head>

<body>
    <div></div>
</body>

</html>